from tkinter import *

root = Tk()

Label(root,bg='red').place(relx=0.5,rely=0.5,relheight=0.75,relwidth=0.75,anchor=CENTER)
Label(root,bg='yellow').place(relx=0.5,rely=0.5,relheight=0.5,relwidth=0.5,anchor=CENTER)
Label(root,bg='green').place(relx=0.5,rely=0.5,relheight=0.25,relwidth=0.25,anchor=CENTER)

mainloop()
